Navegando por Assunto "Plasticidade neuronal"

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Acesso aberto (Open Access)
Análise quantitativa de neurônios imunomarcados para parvalbumina no hipocampo e núcleo magnocelular do istmo em Actitis macularius no período de invernada
(Universidade Federal do Pará, 2020-02) GUERREIRO, Luma Cristina Ferreira; DINIZ, Cristovam Wanderley Picanço; http://lattes.cnpq.br/2014918752636286; DINIZ, Daniel Guerreiro; http://lattes.cnpq.br/3269424921125406; https://orcid.org/0000-0001-7369-2165
It is already known that parvalbumin (PV) neurons have their number modified in face of social, multisensory and cognitive stimuli, both in mammals and birds. However, nothing is known about its plasticity in long-distance migratory shorebirds during wintering period. Here we investigated in four distinct temporal windows of the wintering period, the plasticity of PV neurons of two brain areas of the spotted sandpiper (Actitis macularius) which includes in its migratory journey multiple stopovers for feeding and resting. We used PV as a marker of a subpopulation of inhibitory neurons and count them in the hippocampal formation (HF) and magnocellular nucleus of tectal isthmus (IMC). Based on previous evidence that HF is involved in learning and memory and social interaction, and IMC is essential for control of head and neck and eyes movements, we tested the hypothesis that PV neurons would increase in HF and remain unchanged in IMC. For this, we used the optical fractionator to estimate cell number. Brains were processed for PV immunostaining, followed by estimates of the number of PV neurons of the areas of interest. As compared with migratory rest 1, PV neurons estimates showed significant increase in the hippocampal formation of premigration group. We suggest that parvalbuminergic neurons proliferation is part of the adaptive changes of the hippocampal circuits involved with the migratory process back to the reproductive niches in north hemisphere.
Acesso aberto (Open Access)
Distribuição espacial e temporal das redes perineuronais durante o desenvolvimento pós-natal do córtex pré-frontal
(Universidade Federal do Pará, 2022-04) COIMBRA, Gabriele dos Santos; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; https://orcid.org/0000-0003-3794-4710
The mammalian prefrontal cortex (PFC) is the cerebral cortex area involved in processing several functions as cognition and complex motor control for social interactions. In this PFC area, there is no duration of the time window definition about its critical period of plasticity. One of the potential biological markers for this may be the Perineuronal Nets (PNNs). The present work aimed to examine the developmental time course of PNN formation focusing on the medial prefrontal cortex (mPFC) of rats using histochemistry with Vicia villosa agglutinin. We use 21 male rats Rattus novergicus, wistar lineage, which were randomly divided into seven experimental groups, composed of 3 animals in each group, as follows: group at 7, 14, 20, 26, 58, 75, and 135 postnatal days, respectively. We found that in PFC, PNNs appear at P26 with a small number of Vv+ cells, increasing in total numbers until adulthood. The results of the present study demosntrate the temporal development of PNN formation in the Wistar rats mPFC, and we suggest a time window for the end of the critical period of plasticity in this cortical area (26- 75 postnatal days), there is a progressive decrease in PNNs with immature profile and a concomitant increase in mature PNNs during postnatal development of the mPFC, making this PNNs profile more prevalent at more advanced ages, around 3 months of age, when the animals are already considered young adults.
Acesso aberto (Open Access)
Efeito da competência leitora nas estratégias de organização perceptual da cena visual em escolares
(Universidade Federal do Pará, 2023-02) RESQUE, Deusa Priscila da Silva; MATOS, Felipe de Oliveira; http://lattes.cnpq.br/4207066833785568; https://orcid.org/0000-0002-4926-4694; PEREIRA JUNIOR, Antonio; http://lattes.cnpq.br/1402289786010170; https://orcid.org/0000-0002-0808-1058
The current Brazilian educational scenario, evaluated by different national and international indicators, has shown alarming results in mathematics, science and especially in reading. The country is in the last positions in all evaluations. For the change of this scenario, urgent educational measures that respect the student's biological and social development are necessary. The applied neurosciences to education emerge as a theoretical model of aid for pedagogical practices that aim to improve quality in education. An important contribution of neurosciences in education is focused on reading, through a theoretical/practical contribution on brain functioning those points more effective paths for literacy with a view to reading competence. In this sense, it was possible to understand that the human species has not yet developed a specific neural system for reading, using other brain structures for this function, ie literacy depends on a neural recycling process of brain structures associated with Sensory, motor and language functions, as is the case with brain regions associated with faces recognition, to accommodate the decoding of the written word. The aim of this study is to investigate reading in school -age children. To this end, the present thesis divided into two studies: Study 1 that investigates the inhibition of the generalization of letters in mirror in school -age children and the study 2 that investigates the relationship between reading competence and perceptual organization strategies of the visual scene in schools . Both studies were conducted in three public schools in the Belém do Pará Metropolitan Region, Brazil. Altogether two hundred and thirty -one subjects aged 6 to 10 years (113 boys, 8.2 ± 1.4 years and 118 girls, 8.2 ± 1.4 years), enrolled 1 to 5th years, were recruited, 1,2 ± 1.4 years old) elementary School. Among these eighty -eight subjects were students from school 1, fifty -two from school 2 and ninety from the school 3. In all, six tests were applied, each school participated in a different group of tests. Our results show that the performance of boys in the 6-10 year old is different from that of girls in the same age group for the reading competence test, with boys with higher performance, although it is not possible to establish differences between genders to the perceptual closure test. What's more, while boys performed significantly better in the rotation of letters in the older group, girls' performance was similar in both groups. This pattern is reverse for the mirror's task, with the older girls surpassing their younger counterparts and the boys performing similarly in both groups. Since the age period of our sample is not associated with large variations in reproductive steroid levels, we propose that the similarity of performance between younger and older girls in the mental rotation of letters may be associated with society's traditional attitudes and expectations and expectations about the relationship between spatial visual skills and gender. As for the mirror's task, while only girls showed a significant difference between the two age groups, the boys showed improvement, as expected by the mirror generalization inhibition to letters during reading. These findings are relevant to the development of more effective future strategies for optimizing the literacy process of school -age children, combining education and neuroscience. For this, more studies must be performed and the number of subjects investigated should be expanded.